data_global _chemical_name_mineral 'Scottyite' loop_ _publ_author_name 'Janczak J' 'Kubiak R' 'Glowiak T' _journal_name_full 'Acta Crystallographica, Section C' _journal_volume 46 _journal_year 1990 _journal_page_first 1383 _journal_page_last 1385 _publ_section_title ; Structure of barium copper pyrosilicate at 300 K ; _database_code_amcsd 0010169 _chemical_formula_sum 'Ba Cu2 Si2 O7' _cell_length_a 6.866 _cell_length_b 13.190 _cell_length_c 6.909 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 625.697 _exptl_crystal_density_diffrn 4.592 _symmetry_space_group_name_H-M 'P n m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '1/2+x,y,1/2-z' '1/2-x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Ba -0.01300 0.25000 0.95700 0.00810 Cu 0.22230 0.00420 0.79360 0.00610 Si 0.00240 0.13400 0.47290 0.00510 O1 0.09660 0.25000 0.48280 0.00800 O2 -0.17180 0.13380 0.63090 0.00970 O3 -0.05890 0.11210 0.25190 0.01070 O4 0.18280 0.05970 0.53400 0.00670 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Ba 0.00710 0.00910 0.00800 0.00000 0.00080 0.00000 Cu 0.00780 0.00480 0.00550 0.00090 -0.00200 -0.00120 Si 0.00620 0.00380 0.00520 0.00060 -0.00040 -0.00020 O1 0.00620 0.00250 0.01510 0.00000 0.00200 0.00000 O2 0.00960 0.00780 0.01070 -0.00010 0.00510 -0.00290 O3 0.01270 0.01190 0.00740 0.00310 -0.00340 -0.00470 O4 0.01020 0.00460 0.00500 0.00070 -0.00080 0.00210